And - as well as the Cleveland Police dog’s records - investigators are analysing police logs, radio communication, aerial footage and written statements from the officers who were present at the time of the attack.

Ms Collins died in hospital days after she was bitten by the German Shepherd dog.

The 73-year-old had allowed police into the garden of her home in Penrith Road, Park End, to search for a suspect as part of a drugs operation.

Ms Collins suffered injuries to her arm and leg and was taken to Middlesbrough’s James Cook University Hospital.